"or within that planet. Owing to mutual gravitational perturbations, the eccentricities of the planetary orbits vary over time. Mercury, the smallest planet in the Solar System, has the most eccentric orbit. At the present epoch, Mars has the next largest eccentricity while the smallest orbital eccentricities are seen with Venus and Neptune. As two objects orbit each other, the periapsis is that point at which the two objects are closest to each other and the apoapsis is that point at which they are the farthest. (More specific terms are used for specific bodies. For example, ""perigee"" and ""apogee"" are the"
"the Sun, which it orbits every 87.97 days. Kepler-9d Kepler-9d, formerly known as KOI-377.03, is a planet in orbit around the sunlike star Kepler-9. Initially discovered by Kepler spacecraft, a terrestrial planet-searching satellite built and operated by NASA, Kepler-9d is most likely a Super-Earth, with an estimated radius approximately 60% larger than that of Earth's, although its exact mass cannot be determined. Kepler-9d orbits Kepler-9 every 1.56 days at a distance of .0273 AU from its star, an extremely close distance. Although Kepler-9d is the closest planet to its star in its system, it is named Kepler-9d instead of Kepler-9b"
"Venus's orbit is the closest to circular, with an eccentricity of less than 0.01. When Venus lies between Earth and the Sun in inferior conjunction, it makes the closest approach to Earth of any planet at an average distance of . The planet reaches inferior conjunction every 584 days, on average. Because of the decreasing eccentricity of Earth's orbit, the minimum distances will become greater over tens of thousands of years. From the year 1 to 5383, there are 526 approaches less than 40 million km; then there are none for about 60,158 years. All the planets in the Solar"
"style=""background:#a0b0ff;""| Semimajor axis ! align=center style=""background:#a0b0ff;""| Orbital period ! align=center style=""background:#a0b0ff;""| Eccentricity ! align=center style=""background:#a0b0ff;""| Inclination ! align=center style=""background:#a0b0ff;""| Radius Gliese 581e is the innermost planet and, with a minimum mass of 1.7 Earth masses, is the least massive of the three. Discovered in 2009, it is also the most recent confirmed planet to have been discovered in this system. It takes 3.15 days to complete an orbit. Initial analyses suggested that the planet's orbit is quite elliptical but after correcting the radial velocity measurements for stellar activity, the data now indicate a circular orbit. Gliese 581b is the most"
"mostly circular orbit. In comparison, planet Mercury lies 0.387 AU from the Sun, orbits every 87.97 days, and has an orbital eccentricity of 0.2056. Gliese 3634 b was one of a sample of over 300 very-low-mass stars targeted by astronomers in search of planets that may orbit such stars. Using the High Accuracy Radial Velocity Planet Searcher (HARPS) at La Silla Observatory in Chile, six years of radial velocity data led the astronomers in the discovery of eleven other planets. After these discoveries, the astronomers chose to refocus their search on short-period planets, hoping to follow up after discoveries using"
"Kepler-20e Kepler-20e is an exoplanet orbiting Kepler-20. The planet is notable as it is the first planet with a smaller radius than Earth found orbiting a Sun-like star. The planet is second-closest to the star after Kepler-20b, and at , it is far too hot to have liquid water on its surface. Along with the other four planets in the system, Kepler-20e was announced on 20 December 2011. With a semimajor axis of 0.0507 AUs, Kepler-20e's orbit has a period of 6.098 days (with an extremely small margin of error). The orbit has an inclination of 87.50°, making its transits"
"Venus for the seventh and last time, decreasing its period to 88 or 89 days and allowing it to approach closer to the Sun. The perihelion distances above are from the center of the Sun. For altitude above the surface, subtract one solar radius ≈ 0.7 Gm.<br> By way of comparison, the planet Mercury orbits the Sun at a distance varying from about 46.0 Gm (46,001,200 km) at its closest to about 69.8 Gm (69,816,900 km) at its farthest. Parker Solar Probe Parker Solar Probe (previously Solar Probe, Solar Probe Plus, or Solar Probe+, abbreviated PSP) is a NASA robotic"
"smallest known planet is PSR B1257+12A, one of the first extrasolar planets discovered, which was found in 1992 in orbit around a pulsar. Its mass is roughly half that of the planet Mercury. The smallest known planet orbiting a main-sequence star other than the Sun is Kepler-37b, with a mass (and radius) slightly higher than that of the Moon. Every planet began its existence in an entirely fluid state; in early formation, the denser, heavier materials sank to the centre, leaving the lighter materials near the surface. Each therefore has a differentiated interior consisting of a dense planetary core surrounded"
"WASP-19b WASP-19b is an extrasolar planet, notable for possessing one of the shortest orbital periods of any known planetary body: days or approximately 18.932 hours. It has a mass close to that of Jupiter (1.15 Jupiter masses), but by comparison has a much larger radius (1.31 times that of Jupiter, or 0.13 Solar radii); making it nearly the size of a low-mass star. It orbits the star WASP-19 in the Vela constellation. It is currently the shortest period hot Jupiter discovered as planets with shorter orbital periods have a rocky, metallic or degenerate matter composition. In 2013, secondary eclipse and"
"scattering haze in the atmosphere as well as the element sodium, and additionally confirmed the presence of water. WASP-19b WASP-19b is an extrasolar planet, notable for possessing one of the shortest orbital periods of any known planetary body: days or approximately 18.932 hours. It has a mass close to that of Jupiter (1.15 Jupiter masses), but by comparison has a much larger radius (1.31 times that of Jupiter, or 0.13 Solar radii); making it nearly the size of a low-mass star. It orbits the star WASP-19 in the Vela constellation. It is currently the shortest period hot Jupiter discovered as"
"planets. These usually are limited to the planets from Mercury to Saturn, although some include Uranus. The light sources for the planets are projected onto mirrors which are geared to a motor which drives the images on the dome. Typically the Earth will circle the Sun in one minute, while the other planets will complete an orbit in time periods proportional to their actual motion. Thus Venus, which takes 224.7 days to orbit the Sun, will take 37 seconds to complete an orbit on an orrery, and Jupiter will take 11 minutes, 52 seconds. Some planetariums have taken advantage of"
"solar radii. It is the smallest discovered planet in the Kepler-124 system, and has the closest orbit of the three known planets. Kepler-124b orbits 96% closer to its star than Earth (approximately 3 Earth days), which in the Kepler-124 system is inside the inner limit of the star's habitable zone. Like many Exoplanets discovered by the Kepler telescope, Kepler-124b was found using the transit method. The transit method utilizes the high magnification and numerous instruments on the Kepler telescope to detect slight fluctuations in brightness of a star being observed. These dips can indicate the presence planet and determine certain"
"years. On September 20, 2018, the discovery of an ultra-short period planet was announced, slightly larger than Earth, orbiting the red dwarf LHS 3844. With an orbital period of 11 hours, LHS 3844 b is one of the planets with the shortest known period. It orbits its star at a distance of . LHS 3844 b is also one of the closest known exoplanets to Earth, at a distance of 14.9 parsec. TESS's third discovered exoplanet is HD 202772Ab, a hot Jupiter orbiting the brighter component of the visual binary star HD 202772, located in the constellation Capricornus at a"
"Beta Pictoris b orbits its host star every 21 years at a distance of 9.2 AU (about the same as Saturn's distance, which is about 9.55 AU). It receives 11% of the amount of sunlight that Earth does from the Sun. In 2014, the rotation period of Beta Pictoris b was calculated from the broadening of its carbon monoxide infrared absorption line. This makes it, , the first extrasolar planet to have its rotation rate measured. With a rotation period of 8.1 hours, it is the fastest-spinning planet known. Its rotation period is faster than that of Jupiter, which has"
"eye of an observer on Earth. HD 8574 is a large planet that orbits its host star every 227.55 days at a distance of 0.77 AU, or 77% the mean distance between the Earth and the Sun. HD 8574 b has, of the six planets announced in a November 2003 discovery paper, the shortest orbit. The planet has an estimated mass of 2.11 times Jupiter's mass. HD 8574 b has a measured orbital eccentricity of 0.288, denoting an elliptical orbit. Jupiter, in comparison, orbits the Sun with an orbital eccentricity of 0.016, which is far more circular. HD 8574 b"
"Earth's orbit All celestial bodies in the Solar System, including planets such as our own, orbit around the Solar System's centre of mass. The sun makes up 99.76% of this mass which is why the centre of mass is extremely close to the sun. Earth's orbit is the trajectory along which Earth travels around the Sun. The average distance between the Earth and the Sun is 149.60 million km (92.96 million mi), and one complete orbit takes days (1 sidereal year), during which time Earth has traveled 940 million km (584 million mi). Earth's orbit has an eccentricity of 0.0167."
"to 56 km.) The albedo is about 7%, comparable to that of the Earth's Moon. 580 Selene Selene (minor planet designation: 580 Selene) is a minor planet orbiting the Sun in the asteroid belt. The name Selene is that of an ancient Greek goddess of the Moon. This body orbits the Sun nearly midway between the orbits of Mars and Jupiter. The orbital eccentricity is slightly lower than that of Mars. Based on its light curve, Selene has an estimated rotation period of 0.3947±0.0004 days, or just under 9.5 hours. During each rotation, the apparent magnitude varies by 0.27. The"
"observable from the Solar System. Like the other planets of the system, the planet has a high maximum eccentricity of 0.28, but the lowest in that system. Kepler-20e Kepler-20e is an exoplanet orbiting Kepler-20. The planet is notable as it is the first planet with a smaller radius than Earth found orbiting a Sun-like star. The planet is second-closest to the star after Kepler-20b, and at , it is far too hot to have liquid water on its surface. Along with the other four planets in the system, Kepler-20e was announced on 20 December 2011. With a semimajor axis of"
"Sun's mass and that is orbited by a white dwarf, Sirius B. The nearest brown dwarfs are the binary Luhman 16 system at 6.6 light-years. Other systems within ten light-years are the binary red-dwarf system Luyten 726-8 (8.7 ly) and the solitary red dwarf Ross 154 (9.7 ly). The closest solitary Sun-like star to the Solar System is Tau Ceti at 11.9 light-years. It has roughly 80% of the Sun's mass but only 60% of its luminosity. The closest known free-floating planetary-mass object to the Sun is WISE 0855−0714, an object with a mass less than 10 Jupiter masses roughly"
"by the Apollo program. </math>, where ""m"" is the mass of Earth, ""a"" is an astronomical unit, and ""M"" is the mass of the Sun. So the radius in AU is about formula_1.</ref> Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. According to radiometric dating and other sources of evidence, Earth formed over 4.5 billion years ago. Earth's gravity interacts with other objects in space, especially the Sun and the Moon, Earth's only natural satellite. Earth revolves around the Sun in 365.26 days, a period known as an Earth year."
"is one third of the Sun. Kepler-42 has an appreciable proper motion of up to 431±8 mas/yr. Due to its small size and low temperature, the star's habitable zone is much closer to the star than Earth is to the Sun. On 10 January 2012, using the Kepler Space Telescope three transiting planets were discovered in orbit around Kepler-42. These planets' radii range from approximately those of Mars to Venus. The Kepler-42 system is only the second known system containing planets of Earth's radius or smaller (the first was the Kepler-20 system pictured at left). These planets' orbits are also"
"(394130) 2006 HY51 orbits the Sun at a distance of 0.1–5.1 AU once every 4 years and 2 months (1,527 days). Its orbit has an eccentricity of 0.97 and an inclination of 33° with respect to the ecliptic. It is the asteroid with the third-smallest known perihelion of any known object orbiting the Sun. Its extreme orbital eccentricity brings it within 0.081 AU of the Sun (26% of Mercury's perihelion) and as far as 5.118 AU from the Sun (making it a Jupiter-grazer). It has a minimum orbit intersection distance with Earth of , equivalent to 41.5 lunar distances. According"
"Proxima Centauri b Proxima Centauri b (also called Proxima b or Alpha Centauri Cb) is an exoplanet orbiting in the habitable zone of the red dwarf star Proxima Centauri, which is the closest star to the Sun and part of a triple star system. It is located about 4.2 light-years (1.3 parsecs, 40 trillion km, or 25 trillion miles) from Earth in the constellation of Centaurus, making it the closest known exoplanet to the Solar System. Proxima Centauri b orbits the star at a distance of roughly with an orbital period of approximately 11.2 Earth days, and has an estimated"
"to have a hot Jupiter-type planet that has a minimum mass of 48% of Jupiter's, and takes only 3.49 days to complete an orbit. WASP-34 is a sunlike star of spectral type G5V that has 1.01 ± 0.07 times the mass and 0.93 ± 0.12 times the diameter of the Sun. It has a planet 0.59 ± 0.01 times as massive as Jupiter that takes 4.317 days to complete an orbit. The system is 432 ± 3 light-years distant from Earth. The Crater 2 dwarf is a satellite galaxy of the Milky Way, located approximately 380,000 light-years from Earth. NGC"
"cause large momentary increases in the emission of X-rays as well as visible light. This would be lethal to Earth-type life on planets near the flare star. In 2018, a planet was discovered orbiting 40 Eridani A with a minimum mass of Earth masses. The planet has an orbit of 42 days, and lies considerably interior to the habitable zone, receiving 9 times more stellar flux than Earth, which is an even greater stellar flux amount than Mercury, the innermost planet in our solar system, on average receives from our Sun. It is one of the closest Super-Earths known, the"
"System orbit the Sun in a counterclockwise direction as viewed from above Earth's north pole. Most planets also rotate on their axes in an anti-clockwise direction, but Venus rotates clockwise in retrograde rotation once every 243 Earth days—the slowest rotation of any planet. Because its rotation is so slow, Venus is very close to spherical. A Venusian sidereal day thus lasts longer than a Venusian year (243 versus 224.7 Earth days). Venus's equator rotates at , whereas Earth's rotates at . Venus's rotation has slowed down in the 16 years between the ""Magellan"" spacecraft and ""Venus Express"" visits; each Venusian"
"of Kepler-10b, a rather large confidence interval. Its radius is the second smallest of the six planets discovered in the system at 2.61 times the radius of Earth. Kepler-11f has a density of about 0.7 g/cm, comparable to that of the Solar System's least dense planet, Saturn. Kepler-11f is the fifth planet from Kepler-11, orbiting its host star every 46.68876 days at a distance of 0.25 AU. Its orbital eccentricity is unknown. In comparison, Mercury orbits the Sun every 87.97 days at a distance of 0.387 AU. Kepler-11f has an orbital inclination of 89.4°; it can be seen almost edge-on"
"() is the ruling planet of Gemini and is exalted in Virgo and/or Aquarius. In classical Roman mythology, Mercury is the messenger of the gods, noted for his speed and swiftness. Echoing this, the scorching, airless world Mercury circles the Sun on the fastest orbit of any planet. Mercury takes only 88 days to orbit the Sun, spending about 7.33 days in each sign of the zodiac. Mercury is so close to the Sun that only a brief period exists after the Sun has set where it can be seen with the naked eye, before following the Sun beyond the"
"Although COROT-7b's mass remains uncertain, with a range between 2 and 8 Earth masses, its radius and orbital period are well known from COROT photometry: it orbits very close to its star (1/23rd the distance from the Sun to Mercury) with an orbital period of 20 hours, 29 minutes, and 9.7 seconds and has a radius of 1.58 Earth radii. COROT-7b has the shortest orbit of any planet known at the time of its discovery. COROT-7b has a maximum surface temperature between 1800 and 2600 °C (3300 to 4700 degrees Fahrenheit). Due to the high temperature, it may be covered"
"580 Selene Selene (minor planet designation: 580 Selene) is a minor planet orbiting the Sun in the asteroid belt. The name Selene is that of an ancient Greek goddess of the Moon. This body orbits the Sun nearly midway between the orbits of Mars and Jupiter. The orbital eccentricity is slightly lower than that of Mars. Based on its light curve, Selene has an estimated rotation period of 0.3947±0.0004 days, or just under 9.5 hours. During each rotation, the apparent magnitude varies by 0.27. The approximate diameter of this asteroid is 46 km. (Some sources list a diameter of up"
"July 2015, Astronomy & Astrophysics said they found a planetary system with three super-Earths orbiting a bright, dwarf star. The four-planet system, dubbed HD 219134, had been found 21 light years from Earth in the M-shaped northern hemisphere of constellation Cassiopeia, but it is not in the habitable zone of its star. The planet with the shortest orbit is HD 219134 b, and is Earth's closest known rocky, and transiting, exoplanet. In February 2016, it was announced that NASA Hubble Space Telescope had detected hydrogen and helium (and suggestions of hydrogen cyanide), but no water vapor, in the atmosphere of"
"and the hunt. The minor planet orbits the Sun at a distance of 32.6–108.3 AU once every 591 years and 4 months (215,992 days). Its orbit has an eccentricity of 0.54 and an inclination of 29° with respect to the ecliptic. It is currently 39.1 AU from the Sun and reach perihelion in 2038. A ten-million-year integration of the orbit shows that this object is in a 2:7 resonance with Neptune. A first precovery was taken by the Near-Earth Asteroid Tracking at Palomar Observatory in 2002, extending the minor planet's observation arc by 8 years prior to its discovery observation."
"1998 KY26 KY26 orbits the Sun at a distance of 1.0–1.5 AU once every 16 months (500 days). Its orbit has an eccentricity of 0.20 and an inclination of 1° with respect to the ecliptic. It has an Earth minimum orbital intersection distance of , which translates into 0.93 lunar distances. As a result, KY26 is one of the most easily accessible objects in the Solar System, and its orbit frequently brings it on a path very similar to the optimum Earth–Mars transfer orbit. This, coupled with the fact that it is water-rich, makes it an attractive target for further"